title: Approach for measuring the angle of hallux valgus.
abstract: BACKGROUND
  There is medium correlation between the current anthropometric method and the radiography in the angle of hallux valgus (AoH) measurement, so this study aimed at designing a reliable and more accurate approach to measure the AoH (AoH).
  
  
  METHODS
  Fifteen age, body weight, and height matched male students were included and those with foot disorders, deformities, or injuries were excluded from the study. The dorsal protrusions of the first metatarsal and the hallux were marked by palpating from three experienced observers; then their barefoot model in standing was collected by a three dimensional laser scanning system. The AoH was defined in the X-Y plane by the angle between the line joining the marks of centre of head and centre of base of metatarsal shaft and the one connecting the marks of the centre of metatarsal head and the hallux. The same procedure was repeated a week later. Besides, other measures based on the footprint, outline, and the radiography were also available for comparisons. Paired t-test, linear regression, and reliability analysis were applied for statistical analysis with significant level of 0.05 and 95% confidence interval.
  
  
  RESULTS
  There were no significant differences recorded between the new method and the radiographic method (P = 0.069). The AoH was superior to the methods of footprint and outline and it displayed a relative higher correlation with the radiographic method (r = 0.94, r (2) = 0.89). Moreover both the inter and intraobserver reliabilities of this method were proved to be good.
  
  
  CONCLUSIONS
  This new method can be used for hallux valgus inspection and evaluation.
authors.affiliation: National Engineering Laboratory for Clean Technology of Leather Manufacture, Sichuan University Chengdu 610065, P. R. China ; Faculty of Technology, Tomas Bata University, Zlin 760 01, Czech Republic.
authors.forename: Jin
authors.initials: J
authors.lastname: Zhou
authors.forename: Petr
authors.initials: P
authors.lastname: Hlavacek
authors.forename: Bo
authors.initials: B
authors.lastname: Xu
authors.forename: Wuyong
authors.initials: W
authors.lastname: Chen
keywords: Hallux valgus; angle of hallux valgus; foot print; radiography; three dimensional laser foot scanning